Stepping stone



FIG. 1 is perspective view of the stepping stone;

FIG. 2 is a top view of the stepping stone, where the bottom view is a mirror image of FIG. 2 devoid of indents;

FIG. 3 is a front view of the stepping stone;

FIG. 4 is a rear view of the stepping stone; and,

FIG. 5 is a right side view of the stepping stone, where the left side view is a mirror image of FIG. 5.

The broken lines depict portions of the stepping stone that form no part of the claimed design. 

CLAIM The ornamental design for a stepping stone, as shown and described. 